The Boeing 727 is one example where the yaw damping systems are an important feature. Yaw dampers in general are very common. Most (all?) airliners have them i

The Boeing 727 is one example where the yaw damping systems are an important feature. Yaw dampers in general are very common. Most (all?) airliners have them in one form or another. The reason for this is that swept wings inherently tend to increase susceptibility to Dutch roll. And yet we don't conclude from this that it's inherently irresponsible of aircraft manufacturers to make airliners with swept wings.